Colon cancer is one of the two most common organ-site cancers in the world, and over 50,000 people per year die in the United States alone from this disease. It is suspected that various mutagens consumed in human foods (either naturally occurring or produced on cooking) may contribute to the incidence of colon cancer. The human intestinal tract is the largest surface area of our body next to our lungs that is in constant contact with the external environment, and in this case the external environment has as high a concentration of bacteria as any place on earth. One strong probability is thus that these intestinal bacteria interact with the mutagens to modify them in some way. Such modifications could be beneficial, making the mutagens less mutagenic, or harmful, making them more mutagenic. A proper assessment of the risk from food mutagens thus requires a knowledge of their interaction with intestinal bacteria, and the long-term objectives of the proposed research are thus to provide the basis for this accurate risk assessment. In addition, if the metabolism turns out to be harmful, the research may indicate ways to reduce or eliminate the harmful metabolic processes. The specific aims of the project are to determine the anaerobic metabolism of the three point fried-food mutagens, IQ, Trp-P-2, and Glu-P-1. These mutagens will be prepared in radiolabeled form and then incubated with a variety of anaerobic micro-organisms. The metabolic products will be detected by radiochromatography, and isolated by HPLC, and their structure will be determined by spectroscopic techniques, especially FAB mass spectrometry. The major metabolic products will then be synthesized and tested to determine their mutagenic activity.